This invention relates to induction systems for internal combustion engines, and especially to an improved way of achieving exhaust gas recirculation therein.
It has been recognized that exhaust gas recirculation, which consists of bringing back a part of the exhaust gas to the intake side of an internal combustion engine is effective in limiting the generation of nitrogen oxides in the combustion chamber. However, too high a concentration of recirculated exhaust gas causes deterioration in the driveability of the vehicle. Therefore, in conventional internal combustion engines provided with exhaust recirculation systems, the recirculation rate is usually limited, which as a practical matter limits the effect in diminishing the amount of nitrogen oxides produced in the combustion chamber.
It is an object of this invention to overcome the above-described shortcoming of the prior art, by providing an improved internal combustion engine which can accommodate a larger rate of exhaust gas recirculation without being accompanied by deterioration of the driveability of the vehicle.